• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Osmosis is the phenomenon of water flow through a semi permeable membrane that blocks the transport of salts or other solutes through it.

Extracts from this document...

Introduction

Osmosis Osmosis is the phenomenon of water flow through a semi permeable membrane that blocks the transport of salts or other solutes through it. Osmosis is a fundamental effect in all biological systems. It is applied to water purification and desalination, waste material treatment, and many other chemical and biochemical laboratory and industrial processes. When two water (or other solvent) volumes are separated by a semi permeable membrane, water will flow from the side of low solute concentration, to the side of high solute concentration. The flow may be stopped, or even reversed by applying external pressure on the side of higher concentration. In such a case the phenomenon is called reverse osmosis. ...read more.

Middle

= cRT where c is the molar solute concentration, R is the gas constant, and T is the absolute temperature. This formula is the same as the pressure formula of an ideal gas. Figure-1 shows connected vessels separated by a semi permeable membrane. If there is only water in the device, the level will be the same at both sides. When solute molecules are added to one side, water will start to flow into it, so that its level will go up at this side, and down at the other side. The system will stabilize when the osmotic pressure is balanced by the hydrostatic pressure generated by the difference in the water levels. ...read more.

Conclusion

This discussion of the flow mechanism usually does not appear in textbooks that deal with osmosis. The effect of the osmotic pressure on the free surface of the solution was first suggested by Hulett in 1902 but received little attention. It seems to have only few proponents since then. Osmosis is a reversible thermodynamic process. That is, the direction of water flow through the membrane can be reversed at any moment by proper control of the external pressure on the solution. Contrary to that, mixing a teaspoon full of sugar in a cup of tea is an irreversible thermodynamic process. There is no way to reverse the process at any given moment and un- mix the sugar back to the spoon. Reversibility is a most important idea of thermodynamics. Osmosis is reversible, while disolving sugar in water, essentially diffusion, is irreversible. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Exchange, Transport & Reproduction section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Exchange, Transport & Reproduction essays

  1. Marked by a teacher

    Investigate the water potential of celeriac.

    5 star(s)

    When performing our experiment, I found a number of sources of error. Firstly, when measuring the depth of the celeriac discs to 2mm, the ruler I used had 1mm gradations. This meant that I could have a potential error of 0.5mm.

  2. Marked by a teacher

    Human Reproductive System

    4 star(s)

    Implantation is the process of attachment of the embryo to the endometrial lining of the uterine wall. It occurs within 1 to 2 days after arrival of the blastocyst in the uterus, a week after fertilisation. The outer membrane of the blastocyst called the trophoblast causes an inflammatory-type response causing the development of the endometrium.

  1. The Endocrine System

    Two types of cell release two different hormones from the pancreas, insulin and glucagon. These hormones target the liver, one or the other depending on the glucose concentration: * In cases where glucose levels increase, less glucagon and more insulin is released by the pancreas and targets the liver.

  2. Blood System Assignemnt

    The lack of oxygen can result in permanent damage to the heart muscle or an area of the brain depending upon how long the vessel is blocked. (Class notes) C. Discuss the structure of the blood and relate this to the function.

  1. the role of the microbiology department

    period Initial incubation a few weeks, but up to ten years or more before symptoms of AIDS may develop. Site of action of pathogen Thelper lymphocytes, macrophages, brain cells. Clinical features HIV infection - flu-like symptoms and then symtomless; AIDS - opportunistic infections including pneumonia, TB, and cancers; weight loss, diarrhoea, fever, sweating, dementia.

  2. Design an experiment to investigate the effect of temperature on the movement of a ...

    This is when the molecules of pigment would have to travel through the membrane in the intrinsic proteins. Below is a graph showing how diffusion means that the molecules move to the side with the lower concentration. (Source- http://www.indiana.edu/~phys215/lecture/lecnotes/lecgraphics/diffusion2.gif) Below is a diagram showing facilitated diffusion with channel proteins and carrier proteins.

  1. Diffusion and Osmosis: Investigating the Processes of Diffusion and Osmosis in a Model Membrane ...

    The kinetic energy of the molecules causes them to collide into each other and switch directions. A result of this molecular motion is diffusion. Diffusion is the random movement of molecules from an area of higher concentration to an area lower concentration.

  2. Investigation in to the movement of osmosis through a selectively permeable membrane, in this ...

    To begin, we used 15mls of Glucose solution- this was the amount needed to cover one piece of potato. The first thing we needed to observe, was how different concentrations affected the weight and length of the potato. We therefore needed to observe each end of the spectrum.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work